VITSEBSK, Belarus -- The pretrial detention of a political activist in eastern Belarus has been prolonged for another six weeks, RFE/RL's Belarus Service reports.

Syarhey Kavalenka, 36, is a member of the Belarusian Conservative Christian Party-Belarusian Popular Front. He was sentenced in January 2010 to three years' "limited freedom" for "illegally displaying the banned Belarusian national flag" in a public place.

As part of that sentence, Kavalenka must report to local parole officers every Thursday and be in his home between 9 p.m. and 6 a.m every day.

Police detained Kavalenka on December 19 and later charged him with violating parole conditions. It is not clear how Kavalenka has violated his parole.

Kavalenka's wife, Alena Kavalenka, was told by police on December 20 that her husband would stay at a pretrial detention center for only three days and therefore she expected him to be released on December 22.

But officials at the Vitsebsk Pershamay district police station told her on the day he was expected to be released that her husband's arrest warrant was reissued and he will remain in the detention center for 45 more days while an investigation is conducted into his alleged parole violation.

Alena Kavalenka told RFE/RL that it is likely that the case against her husband is based on his refusal to sign documents imposing stricter regulations on his parole.

On November 24, parole officers visited the Kavalenkas' home when Syarhey Kavalenka was absent and told his wife that "from now on [your husband] has to stay at home starting from 7:30 p.m [instead of 9 p.m]."

Kavalenka subsequently refused to sign a document confirming that he was informed about and accepts that change.

Alena Kavalenka informed RFE/RL on December 20 that her husband had told her in a court corridor that he has started a hunger strike to protest his case.

If found guilty, Kavalenka could be sent to jail for three years.

In addition to the parole violation, Kavalenka was also officially charged several weeks ago with "verbally insulting police" and "illegally displaying the banned Belarusian national flag in a public place," one of the crimes he was initially sentenced for.